by Scott Bowles, USA TODAY

by Scott Bowles, USA TODAY

The Conjuring,a $20 million horror film facing a raft of new summer films, claimed an easy win at the box office this weekend, earning $41.5 million, according to studio estimates from Hollywood.com.

The debut upended analysts' forecasts, which called for $25 million and, at best, a second-place finish behind the latest big-studio animated offering, the $135 million Turbo.

But Conjuring, a haunted house tale starring Patrick Wilson and Vera Farmiga, garnered surprisingly strong reviews, earning an 85% positive rating among critics on Rottentomatoes.com. And with a 90% thumbs-up score among fans, word of mouth spread quickly about the low-budget horror film, a lucrative sub-genre this year.

In January, the $15 million fright flick Mama opened at the top spot with $28 million on its way to an overall gross of $72 million. Last month, the $3 million The Purge shocked analysts with a No. 1 debut of $34 million and would go on to do $64 million.

Canny marketing and grainy-footage trailers for Conjuring "built a tremendous amount of buzz over the past few months," says Tim Briody, analyst for Boxofficeprophets.com. "And having some of the best reviews of the year for a wide release certainly doesn't hurt, either."

The welcome wasn't so warm for the rest of weekend's newcomers. Despicable Me 2, in its third week of release, was second with $25.1 million.

Turbo, the animated story of a snail with a need for speed, starring Ryan Reynolds, took a disappointing third place with $21.5 million. The movie, which opened Wednesday, has done $31.2 million in five days.

Adam Sandler's Grown Ups 2 was fourth with $20 million, followed by Red 2, the action film starring Bruce Willis and John Malkovich, which did $18.5 million. Analysts expected about $22 million.

The weekend wasn't a good one at the turnstiles for Reynolds. The only other major newcomer, his supernatural cop thriller R.I.P.D., took seventh with $12.8 million. Final figures are expected Monday.

Summer's furious comeback has stalled since the July 4 holiday. Attendance has fallen behind last year's pace by about 3%, Hollywood.com says.